Okay, we are given 3001 and 1586. Let's add them up step by step.

Step 1: We'll start by adding the digits 1 & 6 in column 1 and get 7.

Step 2: We'll start by adding the digits 0 & 8 in column 2 and get 8.

Step 3: We'll start by adding the digits 0 & 5 in column 3 and get 5.

Step 4: We'll start by adding the digits 3 & 1 in column 4 and get 4.

So, 3001 + 1586 = 4587.

